Ovarian hyperstimulation syndrome: strategies for prevention.

Ovarian hyperstimulation syndrome (OHSS) is a serious, iatrogenic complication of ovarian stimulation. The following report is a review of traditional and new strategies to prevent the development of OHSS. Techniques such as reducing the ovarian stimulus, coasting and cryopreservation are discussed. Other more investigative strategies are also summarized, including follicular aspiration, in-vitro maturation of immature oocytes, the use of gonadotrophin-releasing hormone (GnRH) agonists to trigger ovulation and the use of volume expanders such as hydroxyethyl starch. In addition, a review of the internal experience with OHSS at the authors' institution is described. All these preventative approaches are based on current understanding of the physiologic mechanisms involved in the pathogenesis of OHSS.